The present invention relates to an internal combustion engine, particularly to such engines employing means for varying the compression ratio thereof and more particularly to improved means for controlling relative movement of two-part cylinders for such engines. Variable compression ratio (VCR) engines are well known in the art and variations thereof are disclosed in U.S. Pat. No. 2,215,986 issued Sept. 24, 1940 to Stevens, U.S. Pat. No. 2,375,183 issued May 8, 1945 to Arden, U.S. Pat. No. 2,419,450 issued Apr. 22, 1947 to Howard and U.S. Pat. No. 2,769,433 issued Nov. 6, 1956 to Humphreys.
In each of the aforesaid patents, a VCR engine is disclosed in which the combustion chamber volume is varied either by adjusting the piston shape or path or by adjusting the cylinder volume. However, none of the referred to patents shows or suggests the two-part cylinder of the present invention in which an integral combustion chamber is formed by the inner cylinder and the piston, thereby minimizing the loss combustion pressure.
The present invention provides a construction wherein the loss of combustion pressure is minimized and also a construction wherein the loss of hydraulic fluid or oil is also minimized. Moreover, the present invention is relatively simple to construct and can be adapted to a wide variety of internal combustion engines, all without reducing the piston diameter.